ES2301745T3 - PROCEDURE AND DEVICE FOR DISPLACING A SCRAPER BLADE. - Google Patents

Abstract

Procedure for moving a scraper blade (26), adjusted to a cylinder (10) of a printing machine, in the direction of the longitudinal axis of the scraper blade (26), the movement of the scraper blade (26) being subdivided temporarily in movement (50) and stop (52) sections, characterized in that during the printing operation, the duration of the stop sections (52) predominates and because the movement sections (50) are located in each case in operating phases, in which waste is printed.

Description

Procedure and device to move a scraper blade

The invention relates to a method for move a scraper blade, adjusted to a cylinder of one printing machine, in the direction of the longitudinal axis of the scraper blade, being subdivided the movement of scraping of the scraper blade temporarily in sections of movement and stop, as well as a device for Performing the procedure.

In printing machines, they are used generally scraper devices with scraper blades for scratch the surface of a rotating cylinder, for example of a printing cylinder, with the help of a scraper blade. A scraper device of this type has, for example in a gravure machine, the function of cleaning by scratching the smooth polished surface of the gravure cylinder after the inked and before the actual printing process, of so that the printing ink is only in the areas depressed cylinder surface printers Print.

In conventional printing machines the scraper blades are made, as a rule, from of thin steel sheet spring steel, tempered or not tempered. An edge of a scraper blade adjusted to the surface of the print cylinder or weft roller is subject to clear wear at the same time. To increase the Service life of the scraper blade, the knife scraper is subjected to an oscillation in its longitudinal direction, so that the wear of the scraper blade is distributed more possible. The frequency of such an oscillation can worth, for example depending on the production speed, 1 Hz or more, and the elevation of the oscillation can be worth for example up to   40 mm Although by oscillating the scraper blade it Distributes scraper blade wear locally, without however, it is still necessary to change a Worn scraper blade. This requires a machine stop of printing.

In order to continue reducing wear of the scraper blade, scraper blades are used which are ceramized on its wear side facing the print cylinder The duration of the scraper blade is Increase with it several times.

European Patent Application EP 1 362 696 of the applicant discloses the fact of submitting to the blade oscillating scraper with a frequency which is in the band Acoustic or ultrasound band. This measure serves to release dirt from the gravure cylinder. The elevation of Vibration movement can be worth less than 0.2 at the same time mm

Although, on the one hand, a swing is desired side of the scraper blade, in order to reduce wear uneven of the scraper blade, the oscillation can also have a negative effect on printing, given that because of the scraper blade speed differences may result slightly different amounts of ink in the depressions of the printing cylinder, which lead to differences in the ink application on the desired material band to print. In printing it can be determinable, in particular, the difference between an area, in which the scraper blade moves with a uniform speed, and an area, in which a inversion of the direction of movement of the scraper blade. Since the frequency of the oscillation of the scraper blade is frequently coupled with the speed of rotation of the cylinder print is structured, for example in a print to several Quality inks, the movement path of the different scraper blades differently, so that the divergences of individual inks. In the case of an impression to several high quality inks, speeds, directions of movement and changes of direction that appear during the oscillation of the scraper blade may have, despite this, a negative influence on the impression.

From FR 1 396 328 it is known superimpose the oscillating movement of a scraper blade a swing with a multiple period, so that the points of inversion of the first swing movement vary so periodic. Anyway, they continue to produce speeds different from the scraper blade to the point stop investment.

From DE 749 890 a printing machine in which the scraper speed is either uniform or zero during cleaning by scratching the engraving on the gravure cylinder. A scraper movement that deflects it takes place after each scraper period in the vacuum of Print. On machines with a caliper cylinder, which is the twice as large as the gravure cylinder, it is arranged to this particular movement of the idle time of the cylinder.

The invention poses the problem of creating a procedure to move a scraper blade adjusted to a cylinder of a printing machine, with which you can get the highest possible print quality for wear as uniform as possible and as small as possible, as well as creating a machine of printing for the accomplishment of the procedure.

The problem is solved according to the invention. by a procedure of the type mentioned at the beginning in the which, during printing operation, dominates the duration of the stop sections and in which the motion sections are located in each case in phases of operation, in the which waste is printed. Additionally, this issue is resolved. by means of a printing machine according to claim 4. The travel speed of the scraper blade is therefore equal to zero for most of the duration of the print operation

The travel speed given for the most of the duration of printing operation can be valid, in particular, for time intervals which correspond to a temporary portion of 90%, in particular also 99% of the duration of printing operation.

When for most of the duration of the print operation the scraper blade is stopped, it can reduce the negative effects of blade movement scraper on print quality compared to a faster, conventional oscillation of the scraper blade. The smaller a divergent travel speed of zero, the less the travel speed acts on the Print. It is also achieved, for a movement of displacement at intervals, that the scraper blade be displaced, over time, an elevation of several millimeters, so that the wear of the scraper blade is distributes along the length of elevation.

The invention relates to avoiding a uneven wear of the scraper blade with the possibility of an especially high print quality, since during stopping the scraper blade results in an ink application especially uniform on the material to be printed.

The movement of movement of the blade scraper is temporarily subdivided into sections of motion and stop and, during printing operation, the duration of the stop sections. In particular, the duration of the sections of motion may be less than 10 percent of the duration of the stop sections, preferably less than 1 percent. It can also be clearly smaller. The duration of the stop sections should be chosen at the same time preferably from such that during the stopping of the scraper blade no there is still no strong uneven blade wear scraper In this embodiment, the uniformity and, with it, the print quality during scraper blade stop.

On a printing machine in which the material to be printed is removed from a roller and / or rolled on a roller, a roller change leads, as is known, that during printing operation in progress temporarily produce waste. This is the case, for example, when a splice point of the desired material band print, generated during an automatic roller change, goes through the printing mechanism or when a band section is printed the which must be separated, later, during an automatic change of winding roller. For this reason, they are chosen in the procedure according to the invention the movement sections during displacement of the scraper blade preferably temporarily in such a way that they match the production of waste. Print disturbances that are caused by the movement of the scraper blade, do not impair the print result quality, since they are removed together with the waste that is produced anyway.

The subordinate claims put I show advantageous structures of the invention.

The movement of movement of the blade scraper is preferably synchronized automatically with Roller change processes.

The displacement movement can be superimposed on a vibration movement with a frequency of at least 1 Hz, in particular at least 5 Hz. In the case of this vibration movement it can also be an acoustic oscillation or an oscillation ultrasound The vibration movement is preferably carried out in the direction of the longitudinal axis of the scraper blade. It serves, on the one hand, to remove dirt from the depressions of the cylinder or to release them from the scraper blade, as described in the European patent application EP 1 362 696 of the applicant. The movements of the scraper blade that appear during the vibration are not considered part of the "movement of movement" in the sense of the invention, and the stop indicated in claim 1 refers only to the movement of pure displacement without taking into account the
vibration.

The object of claim 4 is a machine of printing with a scraper device, which has a scraper blade that can be adjusted against a cylinder and a displacement device to move the scraper blade in the direction of the longitudinal axis of the scraper blade, the displacement device being formed to carry out a method, according to claim 1, for displacement of the scraper blade adjusted to the cylinder. The device of displacement may be formed to carry out the procedure semi- or completely automatically. Machine Printing has the advantages indicated during the description of the procedure

In a preferred embodiment the scraper device of the machine features an oscillator for the generation of a vibration movement of the scraper blade and the displacement device and the oscillator are formed to carrying out a method according to claim 1, in which the movement of movement is superimposed on a movement of vibration with a frequency of at least 1 Hz, in particular of at least 5 Hz.

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In an embodiment especially Preferred printing machine, the scraper blade is ceramized on its wear side. This enables, during movement of the scraper blade, a duration length of a stop section, without wear uneven scraper blade.

The following explains, from the drawing, some examples of preferred embodiments of the invention.

In the drawing:

Figure 1 shows a schematic view of a gravure machine;

Figure 2 shows a schematic section at along line II-II of Figure 1;

Figure 3 shows a partial section schematic of a gravure machine with a winder;

Figure 4 shows a schematic diagram of a movement of movement with sections of movement and of stop;

Figure 5 shows a schematic diagram of a periodic reciprocating movement;

Figure 6 shows a schematic view of a gravure machine with a scraper device with a oscillator; Y

Figure 7 shows a schematic diagram of sections of a periodic reciprocating movement, which is superimposed on a vibration movement.

The gravure machine represented in the Figure 1 comprises a gravure cylinder 10, a roller inker 12 and a compression cylinder 14, which are supported rotatable between side pieces 16, 18 of a frame machine. In this case, no devices have been represented corresponding drive and adjustment since they are not essential for the understanding of the invention.

The inking roller 12 is, at its apex upper, in contact with the rotogravure cylinder 10 and immerse, with its lower vertex, in an ink tank 20, as can be clearly recognized in Figure 2. The roller Inker 12 therefore takes printing ink from the tank of ink 20 and transfers it onto the perimeter surface of the gravure cylinder 10, which rotates in the direction of the arrow in Figure 2 and transfers the printing ink over a band of material to be printed 22, which passes between the compression cylinder 14 and the gravure cylinder and that is compressed by the compression cylinder against the cylinder gravure

A scraper device 24 is assigned to the intaglio cylinder 10. This scraper device is known, in a known manner, by a scraper blade 26, which is held in a fastener 28. The fastener is mounted on a shaft 30, which it extends between two levers 32, 34. The lower ends of the levers 32, 34 rest on a rotating shaft 36, with which the entire scraper device 24 can be folded against the perimeter of the gravure cylinder so that its surface is cleaned by scratching with the edge of the scraper blade 26. In this way the printing ink absorbed by the inking roller 12 is removed from the areas of the surface of the smooth gravure cylinder 10, which do not print, so that the ink of printing is already unique-
mind in depressed areas, which generate the impression on the band of material to be printed 22.

On the lever 34, a device is arranged displacement 38, with which the fastener can be displaced 28 and consequently the scraper blade 26 in the direction of the longitudinal axis of the scraper blade, with respect to the levers 32, 34, as indicated by the double arrow on the Figure 1. The displacement device 38 forms by consequently a transverse displacement device, which generates a movement of the blade of the scraper blade 26 with with respect to the gravure cylinder 10 in the transverse direction with respect to the direction of the march of the material band that it is desired to print 22, that is in the axial direction of the cylinder of gravure Instead of the displacement device 38 you can a displacement device is provided which moves the entire scraper device 24, together with the levers 32, 34, in the indicated direction.

Figure 2 shows on the bottom side of the scraper blade 26 a ceramic layer 40 whereby reduces the wear of the scraper blade 26 by contact with the rotogravure cylinder 10 that rotates.

Figure 3 shows that the band of material that it is desired to print 22, after printing on the machine gravure, is rolled, by means of deflection rollers 42 and a compensating roller 44, on the winding roller 46. A full winding roller can be replaced, so known, automatically or manually, by a new coil 48, the which then forms the inside of the next roller of winding In this case, the support of the deflector rollers 42 and winding roller 46 as well as the corresponding devices of the coiler, since no They are essential for understanding the invention.

In Figures 4 and 5 two are described movement movements of the scraper blade 26, at which displacement device 38 of the scraper device 24. The movement movement has place in each case in the direction of the longitudinal axis of the scraper blade In each case a position of the scraper blade 26 which varies over time in the Direction of movement movement. To make clear differences between the different movement movements, the diagrams of Figures 4 and 5 as well as Figure 7, which described below, they are not represented to each other proportionally.

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Figure 4 shows a movement of displacement of the scraper blade 26, which is subdivided  temporarily in motion sections 50 and stop sections 52. At the same time the duration of stop sections 52 is valid at least one hundred times the duration of the movement sections 50. During a movement section 50, the scraper blade 26 a certain measure is displaced in the direction of the longitudinal axis  of the scraper blade. In Figure 4, two are represented movement sections 50, in which the scraper blade 26 it is displaced in each case in the same direction and the same measure, for example 1 mm. After the scraper blade 26 has been displaced, during several sections of movement 50, up to one fixed position, an inversion of the movement takes place. The same time you can vary the extent to which the scraper blade during the following sections of movement.

Unlike the example represented in the Figure 4, can also take place during the conservation of the direction of movement a variation of the extent to which it is the scraper blade displaced during a movement section 50. In order to ensure the highest possible uniformity of the wear of the scraper blade 26, it is advantageous to vary from such way the measures in which the scraper blade is displaced, which a position adopted once by the scraper blade is adopted again after as long as possible.

Motion sections 50 match temporarily with winding roller changes 46. During stop sections 52, in each case, a winding roller 46. In sensor not shown, it records the coil radius on winding roller 46 and triggers, when a roller change is necessary, the section of movement 50. The roller change itself is initiated then with a temporary delay such that the material band that you want to print is cut, during the change of roller, approximately at the point that was printed at the time of the movement section 50. In case because of the movement of the scraper blade 26 has undermined the image, the point of the error is therefore in a section of the band of material to be printed, which forms the end of the old winding roller or the beginning of the new winding roller and that is removed later without more like scrap

Figure 5 shows the movement of displacement according to another exemplary embodiment. He displacement movement is, in this case, a movement of periodic swinging with a period of one hour. The Swing elevation is, for example, ± 20 mm. The travel speed of the scraper blade 26 is, by therefore, in the range between 0 and 0.04 mm / s. This very low scrolling speed influences printing on Any case to a very small extent. Others are imaginable too forms of oscillation, for example a triangular oscillation.

Another image improvement is achieved through a vibration movement, which is explained below, which superimposes the movement of the scraper blade 26.

Figure 6 shows a gravure machine modified with respect to Figure 1, in which on the tree 30, between the displacement device 38 and the fastener 28, is has introduced an oscillator 54, which subjects the fastener 28 and with it also the scraper blade 26 at high oscillations frequency in the parallel direction relative to the axis of the cylinder gravure 10, that is parallel with respect to the direction of displacement of the scraper blade 26. The oscillator 54 forms consequently another transverse displacement device, the which generates a vibration movement of the blade edge scraper 26, which is superimposed on the movement of displacement. The frequency of the vibration movement is in the band of the ultrasound, so that the vibration oscillations of the scraper blade 26 have the shape of ultrasound waves in course, which spread to the opposite end of the scraper blade and are absorbed there by a shock absorber 56 sandwiched between lever 32 and fastener 28.

The frequency can also be, however, clearly smaller and the oscillator 54 can be, for example, a acoustic oscillation generator. Also, you can conceive a even lower frequency of vibration movement. The elevation of vibration movement can be very small, it can be for example less than 0.2 mm.

Figure 7 shows two sections of a movement of the scraper blade 26 according to the Figure 5, to which a vibration movement is superimposed. In a section 58 of the movement of movement varies gradually the middle position of the scraper blade 26 while the scraper blade 26 performs at the same time a vibration with a much lower elevation around the central position. In a second section 60 there is an inversion of the direction of the movement of movement. Vibration movement superimposed, in this case, results in it also not occurring in the reversal point of the movement of movement no stop of the scraper blade 26. By the movement of overlapping vibration shown in Figure 7 is possible, facing the displacement movement shown in Figure 5, without movement  of superimposed vibration, another increase in print quality, or for the same quality, a travel speed greater than The scraper blade.

Examples of embodiments represented refer, in each case, to a machine gravure The invention cannot be used, however, only with gravure machines, but also with others printing machines

Claims (7)

1. Procedure for moving a scraper blade (26), fitted to a cylinder (10) of a printing machine, in the direction of the longitudinal axis of the scraper blade (26), the movement of the scraper blade offset being subdivided ( 26) temporarily in movement (50) and stop (52) sections, characterized in that during the printing operation, the duration of the stop sections (52) predominates and because the movement sections (50) are located in each case in phases of operation, in which waste is printed. 2. A method according to claim 1, characterized in that a vibration movement with a frequency of at least 1 Hz, in particular at least 5 Hz, is superimposed on the displacement movement. Method according to claim 2, characterized in that the vibration movement is carried out in the direction of the longitudinal axis of the scraper blade (26). 4. Printing machine with a scraper device (24), which features an adjustable scraper blade (26) against a cylinder (10) and a displacement device (38) to move the scraper blade (26) in the direction of the axis length of the scraper blade (26), whose displacement device (38) is formed to give rise to a displacement movement of the scraper blade (26), which is temporarily subdivided into motion sections (50) and stop (52), characterized in that the displacement device (38) is formed to give rise to the displacement movement such that during the printing operation the duration of the stop sections (52) predominates and because the movement sections (50 ) are, in each case, in operational phases, in which waste is printed. 5. Printing machine according to claim 4, characterized in that the scraper device (24) has an oscillator (54) for generating a vibration movement of the scraper blade (26) and the displacement device (38) and the oscillator (54) are formed to cause the displacement movement and the vibration movement of the scraper blade (26) such that the displacement movement is superimposed on the vibration movement and that it has a frequency of at least 1 Hz , in particular at least 5 Hz. 6. Printing machine according to claim 5, characterized in that the displacement device (38) and the oscillator (54) are formed to cause the displacement movement and the vibration movement of the scraper blade (26), such that The vibration movement is carried out in the direction of the longitudinal axis of the scraper blade (26). 7. Printing machine according to one of claims 4 to 6, characterized in that the scraper blade (26) is ceramized on its wear side.